Synthesis and characterization of supported stabilized palladium nanoparticles for selective hydrogenation in water at low temperature.

Anish Patel,Anjali Patel

doi:10.1039/d1ra00239b

Abstract

Zirconia supported vacant phosphotungstate stabilized Pd nanoparticles (Pd–PW11/ZrO2) were prepared using a simple impregnation and post reduction method, characterized and their efficiency for selective C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C hydrogenation of unsaturated compounds explored. The establishment of a hydrogenation strategy at low temperature using water as solvent under mild conditions makes the present system environmentally benign and green. The catalyst shows outstanding activity (96% conversion) with just a small amount of Pd(0) (0.0034 mol%) with high substrate/catalyst ratio (29 177/1), TON (28 010) and TOF (14 005 h−1) for cyclohexene (as a model substrate) hydrogenation. The catalyst was recovered by simple centrifugation and reused for up to five catalytic cycles without alteration in its activity. The present catalyst was found to be viable towards different substrates with excellent activity and TON (18 000 to 28 800). A study on the effect of addenda atom shows that the efficiency of the catalyst can be enhanced greatly by increasing the number of counter protons. This challenging strategy would greatly benefit sustainable development in chemistry as it diminishes the use of organic solvents and offers economic and environmental benefits as water is cheap and non-toxic.

Highlights

Palladium nanoparticles (PdNPs) are one of the most studied catalysts for organic transformations and historically dominant over other metals, and they still serve as a central tool for innumerable important organic transformations and total synthesis.[1]
Thermal stability of Pd–PW11/ZrO2 was evaluated by TGA and the obtained curve is plotted in Fig. S2.† Curve indicates 8.13% weight loss in the temperature range of 50 to 110 C due adsorbed water molecule
Selected area electron diffraction (SAED) image of Pd–PW11/ZrO2 shows the noncrystalline nature of highly dispersed Pd in the synthesized material (Fig. S3†)

Summary

Introduction

Palladium nanoparticles (PdNPs) are one of the most studied catalysts for organic transformations and historically dominant over other metals, and they still serve as a central tool for innumerable important organic transformations and total synthesis.[1]. Rst time we present a simple engineering method for PdNPs, based on supported mono lacunary tungstophosphoric acid (PW11/ZrO2) as effective stabilizing agent. Stabilized PdNPs via supported mono lacunary tungstophosphoric acid (Pd–PW11/ZrO2) was synthesized by wet chemistry method in two steps.

Results

Conclusion